Various arrangements have been used and described for providing a visual display of stored encoded characters. Generally, the encoded character information is stored in a memory or readout means from which each encoded character is selectively read. The encoded character information is used to control the video information which is modulated on the beam of a cathode ray tube which provides a visual presentation on the tube screen corresponding to the character read from the memory. The characters may be generated on the screen in various ways. One particular arrangement displays each character in the form of a dot matrix written by a plurality of vertically spaced horizontal scans of an electron beam. The video information is pulsed, as determined by the memory readout, during each scan to produce the desired character dot pattern.
To increase the intelligibility of the displayed text, which is composed of successive rows of adscript characters, it is frequently desirable to provide certain characters with unique characteristics available in written or printed format. For example, the operator may find it useful to raise selected characters above their related character row, that is, provide superscript characters; or lower selected characters below their related character row to provide a subscript character. Such editorial freedom is particularly desirable in connection with the display of chemical compounds and other technical data where the use of subscript and superscript characters are, in fact, often times necessary to accurately display the information. Previously, such editorial freedom has not generally been available in connection with the operation of an electronic visual display apparatus.